Few standardized language assessments are adapted to different cultural and linguistic contexts to assess children’s first language (L1) abilities. We introduce the Ivorian Children’s Language Assessment Toolkit for measuring phonological awareness, vocabulary, oral comprehension, and tone awareness in the Abidji, Attié, and Baoulé languages of Côte d’Ivoire. Six hundred and three primary-school children (age 4–14) completed language assessments in their L1 and French. The toolkit provided a reliable and comprehensive assessment of children’s language abilities. We observed age- and grade-related increases in all subtest scores. Still, children scored higher in their L1 compared to French, highlighting the need for language assessments in a bilingual’s two languages to achieve an accurate measure of children’s language abilities. The ability to benchmark children’s scores relative to age- and grade-norms are discussed in the context of language of instruction education policies as well as the potential use of age- and grade-norms in identifying children with language impairment and/or children who are at risk for reading difficulties due to poor language skills.